A procedure has been developed, based on centrifugal elutriation, for obtaining enriched populations of cells from embryonic rat cerebra. Methods designed to obtain purer cell fractions will be pursued. Peripheral nervous system cells will be grown in vitro. The cell surface characteristics of specific types of CNS, PNS and transformed neural cells will be compared. Current studies of the sialoglycolipid composition of solid neuroblastoma tumors will be continued.